This section is intended to provide a background or context to the invention disclosed below. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived, implemented or described. Therefore, unless otherwise explicitly indicated herein, what is described in this section is not prior art to the description in this application and is not admitted to be prior art by inclusion in this section. Abbreviations that may be found in the specification and/or the drawing figures are defined below at the end of the specification but prior to the claims.
Currently, LTE TDD allows for asymmetric UL-DL allocations by providing seven different semi-statically configured TDD UL-DL configurations shown in FIG. 1. These allocations can provide between 40 percent and 90 percent DL subframes. A current mechanism for adapting UL-DL allocation is based on the system information change procedure with 640 ms period. The concrete TDD UL/DL configuration is semi-statically informed by SIB-1 signaling.
During a RAN #58 meeting, a new work item “Further Enhancements to LTE TDD for DL-UL Interference Management and Traffic Adaptation (LTE_TDD_eIMTA)” was approved. The related standardization work has been started since January 2013. In this work item, dynamic TDD UL/DL reconfiguration is a feature for LTE Rel-12 or beyond, whose motivation is to realize the flexibility to have dynamic TDD UL/DL configuration in a TDD system to match the uplink and downlink traffic variations. However, additional improvements could be made in order to realize this flexibility.